InfiniteWheelie Posted January 2 Share Posted January 2 (edited) If you don’t know what hybrid supercapacitors are, they're basically a mix between a supercapacitor and a battery. They retain almost all the benefits of supercapacitors while having an energy density closer to batteries. The lie somewhere in-between, trying to offer the best of both worlds. Skeleton Technologies is a supercapacitor manufacturer known for selling the highest energy density caps to date. They’ve now finished developing their first hybrid supercapacitor which they call “SuperBattery”, set to go into mass production this year. It has 50,000 cycles, 20c continuous charge/discharge (60c peak allows a 1 minute charge), nearly full performance at extreme temperatures, and zero fire risk. They'll come in 60x138mm cylindrical cells with 53wh (136wh/l 65wh/kg). https://1188159.fs1.hubspotusercontent-na1.net/hubfs/1188159/02-DS-SuperBattery-D60-view.pdf As you can see it's basically the perfect battery in every category (excluding energy density). It's 4x less energy dense per volume than the best lithium ion cells available today. However, I’m proposing that these may actually be suitable for high performance electric wheels. One major benefit electric wheels have is that their natural shape allows for at least 2x the battery compared to other PEVs, which helps to partially offset the lower energy density of these cells. I’ve put together a stripped down example of a wheel using these cells (to scale). It's a street wheel with a 23" tire (17" rim) and 160mm pedal clearance. The battery is 28s 1p which equals 84v, 30kw continuous, and 1500wh. Keep in mind, this is over 2x the capacity of most e-bikes, and similar to a mid size e-scooter. What do you think, would the tradeoff be worth it? Edited January 5 by InfiniteWheelie 2 Quote Link to comment Share on other sites More sharing options...
Toad Posted January 3 Share Posted January 3 How far could I go on an Inmotion V8 filled with those cells? Quote Link to comment Share on other sites More sharing options...
InfiniteWheelie Posted January 4 Author Share Posted January 4 (edited) @Toad Well these particular cells are very large. On the 23" wheel I drew they barely fit in both length and diameter. The 1500wh battery would give around 50km of real world range. On a smaller wheel you'd have to arrange them differently, so you'd end up with less cells and range. Edited January 4 by InfiniteWheelie Quote Link to comment Share on other sites More sharing options...
InfiniteWheelie Posted January 5 Author Share Posted January 5 (edited) Here's another configuration I made. It's not as elegant but makes much better use of the space. The battery is 44s 1p which equals 132v, 46kw continuous, and 2300wh. I could definitely live with a battery that size. Another option is 22s 2p (each side of the wheel gets half), giving you redundancy if one side fails. The lower voltage can be accounted for by winding the motor differently. These are just to give a rough idea of what might be possible. Edited January 5 by InfiniteWheelie Quote Link to comment Share on other sites More sharing options...
atdlzpae Posted January 5 Share Posted January 5 2300Wh at 65Wh per kg is 35kg for just the battery. So the whole unicycle would weight about 50kg, if not even more. LiFePo4 is a way more viable chemistry. Heavier than normal lithium ions, but not outrageously so like these capacitors would be. Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted January 5 Share Posted January 5 20C charging is the only thing about capacitors that I find appealing... Your wheel could recharge 80% in 12 minutes, from the common 7kW Level2 EV charging station (plus a very heavy 7kW charger brick). Otherwise, we've got all the performance we can use, with today's NMC chemistries. I think the biggest thing riders want is improvement in energy density and the corresponding EUC weight reduction. E.g.: a 3kwh EUC weighing less than 50lbs. Quote Link to comment Share on other sites More sharing options...
InfiniteWheelie Posted January 5 Author Share Posted January 5 (edited) 8 hours ago, atdlzpae said: 2300Wh at 65Wh per kg is 35kg for just the battery. That's a valid point, and I definitely think the 1500wh example is more practical. The cell arrangement is much simpler, and it would only weigh 22.7kg (4.3kg more than the Master Pro). 5 hours ago, RagingGrandpa said: 20C charging is the only thing about capacitors that I find appealing... Your wheel could recharge 80% in 12 minutes, from the common 7kW Level2 EV charging station (plus a very heavy 7kW charger brick). I'm thinking one step further with DC fast charging, which would give you a 1 minute charge! The cells can actually peak to 60c for 1 minute. 1500wh x 60c = 90kw, which most stations can easily provide. For AC charging, it could come with a 1500w charger for a 1 hour charge. Like I mentioned though, fast charging is not the only benefit. 50k cycles, retains performance and charging below freezing, zero fire risk. These are all big deals themselves, but for this to make sense it does need the 1 minute DC and 1 hour AC fast charging Edited January 5 by InfiniteWheelie Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted January 5 Share Posted January 5 8 minutes ago, InfiniteWheelie said: DC fast charging 90kw 14 hours ago, InfiniteWheelie said: 132v 680 amps for 1 minute? Sorry, dream on... Quote Link to comment Share on other sites More sharing options...
InfiniteWheelie Posted January 5 Author Share Posted January 5 (edited) @RagingGrandpa Actually the 1500wh example is only 84v, so that would be over 1,000a. Come to think of it, even Tesla superchargers max out at 631a. Even a 5 minute charge would still be plenty fast, and only require 214a. Edited January 5 by InfiniteWheelie Quote Link to comment Share on other sites More sharing options...
RagingGrandpa Posted January 5 Share Posted January 5 (edited) How much extra copper are you planning to install in this EUC?! DC fast chargers typically implement a minimum output voltage near 200V also... Quote Combined charging systems, standardized in IEC 62196-3 and SAE J1772 CCS Type 1 in North America and CCS Type 2 in Europe The voltage ranges are 200 – 920 V. And they require a special type of PLC communication with the vehicle in order to work... I think it's impractical for EUC to ever support road car DC EVSE's. Isn't 7kW AC enough? Edited January 5 by RagingGrandpa Quote Link to comment Share on other sites More sharing options...
InfiniteWheelie Posted January 5 Author Share Posted January 5 (edited) @RagingGrandpa The problem with AC charging is that you need to carry your own charger. They can’t fit inside PEVs, and anything over around 1500w (perhaps 3000w at 240v) gets too big to carry around. It’s true that most DC chargers don’t go below 200v, though some go down to 50v. The stickers on Tesla superchargers (which are now open to CCS protocol) say the output voltage is 0-X volts, but I don't know if they actually go that low in practice. Regardless, PEVs would need to be supported by DC chargers. Edited January 8 by InfiniteWheelie Quote Link to comment Share on other sites More sharing options...
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